One type of non-volatile integrated circuit memory uses a floating gate transistor for charge storage. Charge stored on the floating gate is used to manipulate a threshold voltage of the transistor, and in this manner store data. An array of floating gate transistors is included with high voltage program/erase circuitry to form the non-volatile memory. While modern processing techniques allow the floating gate transistors to be made smaller, the high voltage program/erase circuits still require a relatively large surface area because they must be able to withstand the high program/erase voltages, for example about 10 volts. One way to reduce the high voltages necessary for program and erase operations is to make the tunnel oxide of the floating gate transistor thinner. However, reducing the thickness of the tunnel oxide may create data retention problems because electrons stored on the floating gate can leak through the relatively thinner tunnel oxide more easily.
Therefore there is a need for a floating gate transistor having good data retention capabilities while also having a thinner tunnel oxide and lower program/erase voltages.